drivers/hwmon/tmp421.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* tmp421.c
   3  *
   4  * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
   5  * Preliminary support by:
   6  * Melvin Rook, Raymond Ng
   7  */
   8
   9 /*
  10  * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
  11  * Supported models: TMP421, TMP422, TMP423, TMP441, TMP442
  12  */
  13
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/slab.h>
  17 #include <linux/jiffies.h>
  18 #include <linux/i2c.h>
  19 #include <linux/hwmon.h>
  20 #include <linux/hwmon-sysfs.h>
  21 #include <linux/err.h>
  22 #include <linux/mutex.h>
  23 #include <linux/of_device.h>
  24 #include <linux/sysfs.h>
  25
  26 /* Addresses to scan */
  27 static const unsigned short normal_i2c[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
  28                                              I2C_CLIENT_END };
  29
  30 enum chips { tmp421, tmp422, tmp423, tmp441, tmp442 };
  31
  32 /* The TMP421 registers */
  33 #define TMP421_STATUS_REG                       0x08
  34 #define TMP421_CONFIG_REG_1                     0x09
  35 #define TMP421_CONVERSION_RATE_REG              0x0B
  36 #define TMP421_MANUFACTURER_ID_REG              0xFE
  37 #define TMP421_DEVICE_ID_REG                    0xFF
  38
  39 static const u8 TMP421_TEMP_MSB[4]              = { 0x00, 0x01, 0x02, 0x03 };
  40 static const u8 TMP421_TEMP_LSB[4]              = { 0x10, 0x11, 0x12, 0x13 };
  41
  42 /* Flags */
  43 #define TMP421_CONFIG_SHUTDOWN                  0x40
  44 #define TMP421_CONFIG_RANGE                     0x04
  45
  46 /* Manufacturer / Device ID's */
  47 #define TMP421_MANUFACTURER_ID                  0x55
  48 #define TMP421_DEVICE_ID                        0x21
  49 #define TMP422_DEVICE_ID                        0x22
  50 #define TMP423_DEVICE_ID                        0x23
  51 #define TMP441_DEVICE_ID                        0x41
  52 #define TMP442_DEVICE_ID                        0x42
  53
  54 static const struct i2c_device_id tmp421_id[] = {
  55         { "tmp421", 2 },
  56         { "tmp422", 3 },
  57         { "tmp423", 4 },
  58         { "tmp441", 2 },
  59         { "tmp442", 3 },
  60         { }
  61 };
  62 MODULE_DEVICE_TABLE(i2c, tmp421_id);
  63
  64 static const struct of_device_id __maybe_unused tmp421_of_match[] = {
  65         {
  66                 .compatible = "ti,tmp421",
  67                 .data = (void *)2
  68         },
  69         {
  70                 .compatible = "ti,tmp422",
  71                 .data = (void *)3
  72         },
  73         {
  74                 .compatible = "ti,tmp423",
  75                 .data = (void *)4
  76         },
  77         {
  78                 .compatible = "ti,tmp441",
  79                 .data = (void *)2
  80         },
  81         {
  82                 .compatible = "ti,tmp442",
  83                 .data = (void *)3
  84         },
  85         { },
  86 };
  87 MODULE_DEVICE_TABLE(of, tmp421_of_match);
  88
  89 struct tmp421_data {
  90         struct i2c_client *client;
  91         struct mutex update_lock;
  92         u32 temp_config[5];
  93         struct hwmon_channel_info temp_info;
  94         const struct hwmon_channel_info *info[2];
  95         struct hwmon_chip_info chip;
  96         char valid;
  97         unsigned long last_updated;
  98         unsigned long channels;
  99         u8 config;
 100         s16 temp[4];
 101 };
 102
 103 static int temp_from_raw(u16 reg, bool extended)
 104 {
 105         /* Mask out status bits */
 106         int temp = reg & ~0xf;
 107
 108         if (extended)
 109                 temp = temp - 64 * 256;
 110         else
 111                 temp = (s16)temp;
 112
 113         return DIV_ROUND_CLOSEST(temp * 1000, 256);
 114 }
 115
 116 static struct tmp421_data *tmp421_update_device(struct device *dev)
 117 {
 118         struct tmp421_data *data = dev_get_drvdata(dev);
 119         struct i2c_client *client = data->client;
 120         int i;
 121
 122         mutex_lock(&data->update_lock);
 123
 124         if (time_after(jiffies, data->last_updated + 2 * HZ) || !data->valid) {
 125                 data->config = i2c_smbus_read_byte_data(client,
 126                         TMP421_CONFIG_REG_1);
 127
 128                 for (i = 0; i < data->channels; i++) {
 129                         data->temp[i] = i2c_smbus_read_byte_data(client,
 130                                 TMP421_TEMP_MSB[i]) << 8;
 131                         data->temp[i] |= i2c_smbus_read_byte_data(client,
 132                                 TMP421_TEMP_LSB[i]);
 133                 }
 134                 data->last_updated = jiffies;
 135                 data->valid = 1;
 136         }
 137
 138         mutex_unlock(&data->update_lock);
 139
 140         return data;
 141 }
 142
 143 static int tmp421_read(struct device *dev, enum hwmon_sensor_types type,
 144                        u32 attr, int channel, long *val)
 145 {
 146         struct tmp421_data *tmp421 = tmp421_update_device(dev);
 147
 148         switch (attr) {
 149         case hwmon_temp_input:
 150                 *val = temp_from_raw(tmp421->temp[channel],
 151                                      tmp421->config & TMP421_CONFIG_RANGE);
 152                 return 0;
 153         case hwmon_temp_fault:
 154                 /*
 155                  * Any of OPEN or /PVLD bits indicate a hardware mulfunction
 156                  * and the conversion result may be incorrect
 157                  */
 158                 *val = !!(tmp421->temp[channel] & 0x03);
 159                 return 0;
 160         default:
 161                 return -EOPNOTSUPP;
 162         }
 163
 164 }
 165
 166 static umode_t tmp421_is_visible(const void *data, enum hwmon_sensor_types type,
 167                                  u32 attr, int channel)
 168 {
 169         switch (attr) {
 170         case hwmon_temp_fault:
 171         case hwmon_temp_input:
 172                 return 0444;
 173         default:
 174                 return 0;
 175         }
 176 }
 177
 178 static int tmp421_init_client(struct i2c_client *client)
 179 {
 180         int config, config_orig;
 181
 182         /* Set the conversion rate to 2 Hz */
 183         i2c_smbus_write_byte_data(client, TMP421_CONVERSION_RATE_REG, 0x05);
 184
 185         /* Start conversions (disable shutdown if necessary) */
 186         config = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_1);
 187         if (config < 0) {
 188                 dev_err(&client->dev,
 189                         "Could not read configuration register (%d)\n", config);
 190                 return config;
 191         }
 192
 193         config_orig = config;
 194         config &= ~TMP421_CONFIG_SHUTDOWN;
 195
 196         if (config != config_orig) {
 197                 dev_info(&client->dev, "Enable monitoring chip\n");
 198                 i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_1, config);
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int tmp421_detect(struct i2c_client *client,
 205                          struct i2c_board_info *info)
 206 {
 207         enum chips kind;
 208         struct i2c_adapter *adapter = client->adapter;
 209         static const char * const names[] = {
 210                 "TMP421", "TMP422", "TMP423",
 211                 "TMP441", "TMP442"
 212         };
 213         int addr = client->addr;
 214         u8 reg;
 215
 216         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 217                 return -ENODEV;
 218
 219         reg = i2c_smbus_read_byte_data(client, TMP421_MANUFACTURER_ID_REG);
 220         if (reg != TMP421_MANUFACTURER_ID)
 221                 return -ENODEV;
 222
 223         reg = i2c_smbus_read_byte_data(client, TMP421_CONVERSION_RATE_REG);
 224         if (reg & 0xf8)
 225                 return -ENODEV;
 226
 227         reg = i2c_smbus_read_byte_data(client, TMP421_STATUS_REG);
 228         if (reg & 0x7f)
 229                 return -ENODEV;
 230
 231         reg = i2c_smbus_read_byte_data(client, TMP421_DEVICE_ID_REG);
 232         switch (reg) {
 233         case TMP421_DEVICE_ID:
 234                 kind = tmp421;
 235                 break;
 236         case TMP422_DEVICE_ID:
 237                 if (addr == 0x2a)
 238                         return -ENODEV;
 239                 kind = tmp422;
 240                 break;
 241         case TMP423_DEVICE_ID:
 242                 if (addr != 0x4c && addr != 0x4d)
 243                         return -ENODEV;
 244                 kind = tmp423;
 245                 break;
 246         case TMP441_DEVICE_ID:
 247                 kind = tmp441;
 248                 break;
 249         case TMP442_DEVICE_ID:
 250                 if (addr != 0x4c && addr != 0x4d)
 251                         return -ENODEV;
 252                 kind = tmp442;
 253                 break;
 254         default:
 255                 return -ENODEV;
 256         }
 257
 258         strlcpy(info->type, tmp421_id[kind].name, I2C_NAME_SIZE);
 259         dev_info(&adapter->dev, "Detected TI %s chip at 0x%02x\n",
 260                  names[kind], client->addr);
 261
 262         return 0;
 263 }
 264
 265 static const struct hwmon_ops tmp421_ops = {
 266         .is_visible = tmp421_is_visible,
 267         .read = tmp421_read,
 268 };
 269
 270 static int tmp421_probe(struct i2c_client *client,
 271                         const struct i2c_device_id *id)
 272 {
 273         struct device *dev = &client->dev;
 274         struct device *hwmon_dev;
 275         struct tmp421_data *data;
 276         int i, err;
 277
 278         data = devm_kzalloc(dev, sizeof(struct tmp421_data), GFP_KERNEL);
 279         if (!data)
 280                 return -ENOMEM;
 281
 282         mutex_init(&data->update_lock);
 283         if (client->dev.of_node)
 284                 data->channels = (unsigned long)
 285                         of_device_get_match_data(&client->dev);
 286         else
 287                 data->channels = id->driver_data;
 288         data->client = client;
 289
 290         err = tmp421_init_client(client);
 291         if (err)
 292                 return err;
 293
 294         for (i = 0; i < data->channels; i++)
 295                 data->temp_config[i] = HWMON_T_INPUT | HWMON_T_FAULT;
 296
 297         data->chip.ops = &tmp421_ops;
 298         data->chip.info = data->info;
 299
 300         data->info[0] = &data->temp_info;
 301
 302         data->temp_info.type = hwmon_temp;
 303         data->temp_info.config = data->temp_config;
 304
 305         hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
 306                                                          data,
 307                                                          &data->chip,
 308                                                          NULL);
 309         return PTR_ERR_OR_ZERO(hwmon_dev);
 310 }
 311
 312 static struct i2c_driver tmp421_driver = {
 313         .class = I2C_CLASS_HWMON,
 314         .driver = {
 315                 .name   = "tmp421",
 316                 .of_match_table = of_match_ptr(tmp421_of_match),
 317         },
 318         .probe = tmp421_probe,
 319         .id_table = tmp421_id,
 320         .detect = tmp421_detect,
 321         .address_list = normal_i2c,
 322 };
 323
 324 module_i2c_driver(tmp421_driver);
 325
 326 MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
 327 MODULE_DESCRIPTION("Texas Instruments TMP421/422/423/441/442 temperature sensor driver");
 328 MODULE_LICENSE("GPL");